Dry ice refrigerating unit



June 29, 1943.

A. ZIELESCH AL DRY ICE REFRIGERATING UNIT' .4 Sheets-Sheet 1 Filed April 1, 1941 \IT M M 346 Zh .ww m 0 \m m M 5 an Q n u Q Q m5 June 29, 1943. A, z sc r 2,323,270

DRY ICE REFRIGERATING UNIT June 29, 1943. A ZIELESCH ETAL DRY ICE REFRIGERATING UNITj filed April 1, 1941 4 Sheets-Sheet 3 6 5 filzxz'n Zz'elesciz J 1943- A. ZIELESCH ETAL' DRY ICE REFRIGERATING UNIT 4 sheets-sheet 4 Filed April 1, 1941 272 72 ZZ'eZeac/Z 5 WSmz'Z/a Patented June 29, 1943 OFFICE DRY 101-: REFRIGERATING UNIT- Alvin Zielesch and Stanton W. Smith,

Portland, Oreg.

' Application April 1, 1941, Serial No. 386,331

4 Claims. (Cl. 62-915) This invention relates to refrigerating devices and'more particularly to a refrigerating unit for insertion in a refrigerating chamber which may be stationary or movable.

An object of this invention is to provide a refrigerating unit which includes a closed refrigerant system and a cold chamber for receiving a solid cake or body of carbon dioxide (CO commonly know as dry ice, the carbon dioxide acting to maintain the refrigerant in the desired cooled condition.

Another object of this invention is to provide a refrigerating means of this kind wherein the sublimated gas emanating from the carbon dioxide may, if desired, be either partly or completely discharged into the refrigerating chamber where the gas acts as a preserving element for certain food products, such as meats. Where a food is in the refrigerating chamber which will be affected by the gas in an undesired manner, the Sublimated gas may be discharged entirely into the atmosphere.

A further object of this invention is to provide a device of this kind which when mounted in a truck body or the like may be operated from storage batteries or the like, and the door to the coldchamber may be extended through a wall of the truck body so that the dry ice may be renewed without opening a door to the refrigerating chamber.

A further object of this invention is to provide a cooling unit of this kind which is thermostatically controlled and wherein the circulating fan is connected with a normally closed switch, which is connected with the entrance doOr to the refrigerating chamber, so that upon opening of the door the fan will be cut off in order that the cold air in the chamber will not be forced out during the time that the door is, open.

A further object of this invention is to provide a combined refrigerating unit and air circulating means for circulating the cooled air about the refrigerating chamber.

A further object of this invention is to provide a unit of this kind which is so constructed that it will occupy only a very small amount. of space, is light in weight, compact, and may readily be removed from the refrigerating chamber when refrigeration is not desired or is unnecessary.

To the foregoing objects and to others which may hereinafter appear, the invention consists of the novel construction, combination and arrangement of parts as will be more specifically referred to and illustrated in the accompanying drawings wherein are shown embodiments of the invention, but it is to be understood that changes, variations and modifications may b resorted to which fall within the scope of the invention as claimed.

In the drawings:

Figure 1 is a detail front elevation of a refrigerating unit constructed accordingrto an embodiment of this invention,

Figure 2 is a sectional view taken on the line 2-2 of Figure 1,

Figure 3 is a detail rear elevation partly broken away and in section of the unit,

Figure 4 is a sectional view taken on the line 4-4 of Figure 2,

Figure 5 is a diagrammatic view of the cooling system embodied in this unit,

Figure 6 is a diagrammatic view of the electric circuits embodied in this unit,

Figure 7 is a fragmentary side elevation of the lower portion of the unit on the side thereof opposite from that shown in Figure 2,

Figure 8 is a detail front elevation partly broken away and in section of a refrigerating chamber having a unit constructed according toan embodiment of this invention mounted-therein, and

Figure 9 is a sectional view taken on the line 9-9 of Figure 8.

Referring to the drawings the numeral l0 designates generally a cold chamber or housing which is heat insulated in a conventional manner and is provided in the front wall ll thereof with a closure l3. The cold chamber III is adapted to be supported within a refrigerating chamber at a point closely adjacent the upper portion of the chamber and, preferably the cold chamber or housing I0 is supported in dependent relation from the upper portion of the refrigerating chamber by means of a plurality of supporting straps i2, which are secured to the sides of the chamber I 0 by fastening devices ll. The upper ends of the straps l2 are extended above the top wall 15 of the housing It and may be secured in any desired manner to the upper portion of the refrigerating chamber. The lower ends of the supporting straps l2 are provided with rightangularly disposed lower end portions l6 engaging beneath the bottom wall I i of the housing II).

A solid body or cake of carbon dioxide (CO designated as I8 is adapted to be disposed in the interior of the housing or cold chamber l0 and is adapted to rest on the top wall IQ of a closed receptacle 2!]. The receptacle 20 rests substantially on the bottom wall I! of the housing l0 and comprises the top wall iii, a bottom wall 2|, front and rear walls 22 and 23 respectively, and opposite end walls 24 and 25. The receptacle 20 is adapted to have a refrigerant liquid disposed therein, which is adapted to be cooled by the body l8, and preferably the interior of the receptacle I0 is provided with a plurality of opposed baiiles 2B and 21, which are disposed in spaced apart parallel relation and extend from the front and rear walls 22 and 23 respectively thereby providing a tortuous passage for therefrigerant from the intake end 28 to the outlet 29. The upper and lower edges of .the bailles and 21' are fixed in any suitable manner to the top and bottom walls l9 and 2| respectively. The receptacle 2!! is preferably supported in slightly spaced relation to the inner surface of the bottom wall I! of the housing III by means of spacing members 30 which are'interposed between the bottom wall 2: of the -receptacle 29 and the inner side of the bottom wall ll of the housing l0,

A pipe 3| is connected to the outlet port 29 of the receptacle 29 and extends "downwardly through an opening 32 provided in. the bottom wall H. The pipe 3| at its opposite end is connected to a radiator structure, generally designated as 33. The radiator structure 33 includes a coil 34, which is connected at one end to the pipe 3| and is connected at the opposite end to a return pipe 35. The opposite ends of the coil 3| are mounted in substantially U -shaped housing members 36, which are secured to an upper or base member 31. The base member 31 is secured by fastening devices 39 to the under side of the bottom wall H.

The coil 34 includes a plurality of radially arranged bristles or heat exchanging elements 39, which are fixed to the several convolutions of the coil 34 between the end housing members 36. The bristles or heat exchanging members 34 are adapted to dissipate the heat from the coil 34 and, preferably, the bristles or heat exchanging members 39 substantially fill the space between the confronting or inner edges of the housing or coil enclosing members 34 to such an extent that when air is forced through the coils 34 past the bristles or heat exchanging members, the heat from these members will be dissipated in the passing air.

In order to provide a means whereby air may be forced through the coil 34 we have provided a fan motor 49, which is suspended by means of a fan suspending strap 4i secured by fastening devices 42 to the botton wall I1. A fan blade member 43 is secured to the shaft 44 of the. fan motor and is disposed closely adjacent the rear side of the cooler unit 33, so that the fan blade structure 43 will force air through the cooler structure 33 for cooling thereby. A pump member 45 is interposed in the return pipe 35 and is operated by means of an electric" motor 46. The pump 45 and the motor 46 are of conventional construction being of a type capable of being enclosed in a suitable housing and operated either from a storage battery or from commercial electric current. The return pipe 35 includes a branch 41 connected to the pump 45 and the branch 41 is connected to a check valve structure 43. The check valve structure 48 opens upwardly and is adapted to prevent downward flow of the refrigerant from the pipe 49, which connects the check valve 49 with the intake port 38.

In order to provide a means whereby the refrigerant system may be maintained in a filled condition at all times, we have provided an expansion chamber or a reservoir 59, which is provided with ears 5! secured by fastening devices 52 to the rear wall 54 of the housing Ill. The reservoir 53 is substantially rectangular in side elevation being relatively narrow in depth and is provided with a filler cap 55 at the upper portion thereof, which may include an-outwardly opening check valve or vent. The reservoir or expansion member 53 is connected by means of a pipe 56 to a coupling 51, which is interposed in the pipe 3|. The expansion member or reservoir is adapted to be substantially half filled with k liquid at all times, so that the refrigerating ,sys tem will be maintained in a filled condition.

In order to provide a means whereby the two motors 40 and 46 may be automatically operated, we have provided a thermostat 58, which is connected by means of a conductor 59 to a source of electric current supply 60. The current supply 60 may be in the form of a storage battery or may be commercial electric current and a manually operated switch 6l is interposed in the conductor 59 between the battery 60 and the thermostat 68.\ A conductor 62 is connected to the opposite side of the battery 60 and is connected to one side of the pump motor 46. The second conductor 63 is connected at one end to the conductor 62 and is connected to the opposite end of the onev side of the motor 40. The opposite side of the member 40 has a conductor 64 connected thereto and a conductor 65 is connected at' one end to the opposite side of the motor 46 and to the conductor 64; The conductor 64 is connected at its opposite end to one contact 66 of 2. normally closed switch which is disposed in a position for operation by opening and closing of the door or closure l 3.

The switch structure, generally designated as 61, includes a second fixed contact 68, which is connected to the conductor 59 and also includes a bridging member 69, which is adapted to bridge the two contacts 66 and 68. A spring 10 is adapted to engage thebridging member 69 and is adapted to constantly urge the bridging member 59 to a circuit'breaking position. The bridging member 68 is provided with a stem or operator H disposed in a position to contact with the door l3 so that when the door I3 is closed the bridging member 69 will be in a circuit closing position, which is the position 'of this bridging member, shown in Figure 6. When the door I3 is opened in order to insert a cake of carbon dioxide in the cold housing In, the spring 10 will move the bridging member 69 to an open position, and thereby stop the fan motor 40 and also 'stop the pump motor 46. In this manner the circulation of the cold air within the refrigerating chamber within which the unit is mounted, will be stopped during the time that the door l3 of the cold chamber I0 is opened. In certain instances the switch structure 61 may be disposed in a position for operation by opening and closing of the door to the refrigerating chamber within which this unit is positioned instead of being positioned for operation by the cold chamber door l3.

The top wall of the housing ID has a gas outlet pipe 12 connected at one end thereto and a manually operable valve 13 is interposed in the pipe 12. The valve member 13 includes a bypass 14 by means of which the gas passing upwardly through the pipe 12 may be by-passed into the refrigerating chamber within which this unit is positioned. The carbon dioxide gas emanating from the body I8 is of such a character that it will act as a preservative for certain foods, such as meats or the like, so that this gas may be released into the refrigerating chamber. However, where the articles being cooled are liable to be damaged by the carbon dioxide gas, the valve member 13 which may be aconventional 3-way valve may be turned so as to discharge the gas exteriorly of the refrigerating chamber.

In Figures 8 and 9 there-is disclosed a refrigerating unit constructed according to this invention, which is mounted in the side wall 15 of a refrigerating chamber, generally designated as 18. The closure 13 is disposed in a position whereby the closure l3 may be opened or closed without the necessity of opening the door 'll,

which gives access to the chamber 16. In thisv manner the carbon dioxide may be renewed without opening the refrigerating chamber door 11.

This arrangement may be used either for a sta-.

tionary refrigerating chamber or a movable refrigerating chamber such as the body of a refrigerating truck or the like. It will be appreciated that where the cooling unit hereinbefore described is mounted on the inside of a truck and the refrigerating chamber of the truck is substantially completely filled with food articles, it is not desirable that the door to the refrigerating chamber be opened in order to replace the carbon dioxide. In instances of this kind the door l3 may be mounted in the outer wall 15 of the truck body, so that the cooling medium or body l8 may be replenished by merely opening the door l3 to the cold chamber.

In the use and operation of this refrigerating structure, the unit which includes th cold chamber or housing I!) with the motors 40 and 46 and the radiator structure 33 is adapted to be mounted on the interior of the refrigerating chamber within which food articles to be cooled are adapted to be placed. When the switch GI is closed, the circuits to the two motors 40 and 48 will be closed and the thermostat 68, which is of conventional construction, may be set to maintain the desired temperature within the refrigerating chamber. The operation of the fan blade structure 43 by the motor 40 will force air through the cooling coils 34 and past the heat dissipating fins or elements 39, so as to cool the air passing through the coils 34 and this cold air will then be circulated about the interior of the refrigerating chamber.

The refrigerant in the closed system hereinbefore described will be maintained at the desired cold temperature by contact of the carbon dioxide 18 with the receptacle 20. By providing a tortuous passage for the refrigerant through the interior of the receptacle 20, the fluid will be forced to flow back and forth through the receptacle 20 from the intake end 28 to the outlet 29. This liquid is forced through the system by means of the pump 45, which has one end thereof connected to the return pipe and the other or outlet side thereof connected to the branch 41. The upwardly opening check valve 48 in the branch 46 will prevent return flow of the refrigerant fluid when the pump 45 is stopped.

What we claim is:

1. A combined refrigerat ng and air circulating unit for insertion in a refrigerating chamber, comprising a housing adapted to receive a solid body of carbon dioxide, a closed refrigerant system correlated with said housing and including a. flat closed receptacle in said hcusing and constituting an inner bottom therefor adapted to support said solid body, an air cooling coil dependingly supported from said housing, means connecting one end of said coil to said receptacle, means connecting the other end of said coil to laid receptacle, a check valve interposed in said latter connecting means, a fluid circulating means connected with said latter connecting means between said check valve and said coil, a fan disposed adjacent one side of said coil for forcing air through the convolutions thereof, an xpansion chamber and mean connecting said expansion chamber with said first connecting means.

' 2. A combined refrigerating and air circulating unit for insertion in a refrigerating chamber, comprising a housing adapted to receive a solid body of carbon dioxide, a closed refrigerant system correlated with said housing and including a flat closed receptacle in said housing and constituting an inner bottom therefor adapted to support said solid body, an air cooling coil dependingly supported from said housing, means connecting one end of said coil to said receptacle, means connecting the other end of said coil to said receptacle, a check valve interposed in said latter connecting means, a fluid circulating means connected with said latter connecting means between said oheck valve and said coil, a fan disposed adjacent one side of said coil for forcing air through the oonvolutions thereof, an expansion chamber, means securing said expansion chamber to one side of said housing, and means connecting said expansion chamber with said first connecting means.

3. A combined refrigerating and air circulating unit for insertion in a refrigerating chamber, comprising a housing adapted to receive a solid body of carbon dioxide, a closed refrigerant system correlated with said housing and including a flat closed receptacle in said housing and constituting an' inner bottom therefor adapted to support said solid body, an air cooling coil dependingly supported from said housing, means connecting one end of said coil to said receptacle, means connecting the other end of said coil to said receptacle, a check valve interposed in said latter connecting means, a fluid circulating means connected with said latter connecting means between said check valve and said coil, a fan disposed adjacent one side of said coil for forcing air through the convolutions thereof, a gas discharge pip communicating at one end with said housing and at the other end with the atmosphere exteriorly of said chamber, a threeway valve interposed in said pipe and having one side thereof communicating with said chamber for selectively discharging carbon dioxide gas in said chamber and another side of said valve providing for selective gas discharge into the atmosphere.

4. A combined refrigerating and air circulating unit for insertion in a refrigerating chamber having a door, comprising a heat insulated housing adapted to receive a solid body of carbon dioxide, 9. closed heat transferring receptacle in said housing having an inlet and an outlet, a coil dependingly supported below said housing and connected at the opposite ends thereof with said inlet and outlet, means for circulating a refrigerant from said receptacle through said coil and back to said receptacle, a check valve correlated with said coil whereby to maintain the circulation in only one direction, means for forcing air past said coil for cooling thereby, a thermostat connected with said circulating means and said air forcing means and disposed in said chamber, and a normally closed switch biased to a circuit breaking position and disposed in a position for engagement with the chamber door whereby to hold said switch in a circuit closing position when the door is closed, said switch being electrically connected with said thermostat and said circulating means and said air forcing means.

ALVIN ZIELESCH. STANTON W. SMITH. 

